Because of their physical and mechanical properties, polycarbonate resins were found to be eminently suitable for a variety of applications in the medical field. However, those applications, which require sterilization by exposure to ionizing radiation, present a problem since polycarbonate tends to yellow and show increased haze. The relevant art is noted to include U.S. Pat. No. 4,624,972 which disclosed polycarbonate compositions resistant to gamma radiation containing an ester of aromatic polycarboxylic acid and monoalkyl or monoaryl ether of polyglycol. The properties of relevant compositions containing esters based on primary alcohols are disclosed in the '972 document.
U.S. Pat. No. 4,873,271 disclosed a gamma radiation resistant polycarbonate composition containing an ester of a poly(alkylene) oxide as a stabilizer. Also relevant are the following U.S. Patents, all of which relate to polycarbonate compositions rendered resistant to gamma radiation by the incorporation of a stabilizing agent U.S. Pat. Nos.: 5,187,211; 4,804,692; 4,963,598; 4,874,802; 5,006,572; 5,187,208; 5,274,009 and 5,214,078. Lastly, U.S. Pat. No. 5,280,050 disclosed a polycarbonate composition containing a poly(alkylene) oxide oligomer and a halogenated aromatic phthalic acid ester of a primary alcohol. U.S. Pat. No. 5,145,751 is noted for its disclosure of a magnetic recording medium which contains a non-magnetic substrate and a magnetic recording layer coated on the substrate. The magnetic recording layer contains a compound embracing the stabilizer of the present invention.